地球上的熱帶地區(qū)物種繁多。那里千姿百態(tài)、各種各樣的生物遠(yuǎn)比地球上其他溫度較低地區(qū)的物種要多得多。一項(xiàng)新的研究宣稱(chēng)，熱帶地區(qū)生物多樣性的秘密可并非是那必不可少的高溫——一整年持續(xù)不變的穩(wěn)定溫度才是關(guān)鍵所在。
The earth's tropics teem with species. They're far more biologically diverse than the cooler parts of the planet. And scientists have credited higher temperatures and greater amounts of sunlight. But a new study claims that the secret to tropical biodiversity isn't necessarily high temperatures - it's the steadiness of those temperatures the whole year ‘round. When today's biodiversity was taking shape millions of years ago, seasons as we know them didn't really exist. So temperatures all over the planet were much more consistent than they are today, even in regions where the temps were low. Researchers looked at insect diversity today at the temperate Harvard Forest in Massachusetts, in tropical Costa Rica and in the 53-million-year-old McAbee fossil bed in British Columbia. Which back then was steadily temperate. And ancient Canadian insect diversity was much more similar to modern Costa Rica's than to the Harvard Forest's. The work appears in the journal Paleobiology. So we may have been thinking backwards - it's not that the tropics have greater biodiversity. Could be that the seasons of today's temperate zones have diminished the biodiversity that once flowered. And animaled. -Steve Mirsky
地球上的熱帶地區(qū)物種繁多。那里千姿百態(tài)、各種各樣的生物遠(yuǎn)比地球上其他溫度較低地區(qū)的物種要多得多?？茖W(xué)家們認(rèn)為造成這一現(xiàn)狀的原因是由于熱帶地區(qū)有著較高的溫度和更多的日照。但是，一項(xiàng)新的研究宣稱(chēng)，熱帶地區(qū)生物多樣性的秘密可并非是那必不可少的高溫——一整年持續(xù)不變的穩(wěn)定溫度才是關(guān)鍵所在。 現(xiàn)今的生物多樣性是在數(shù)百萬(wàn)年前就已開(kāi)始形成了，我們所知的四季當(dāng)時(shí)還并不存在。因此，地球這整個(gè)星球的溫度都比現(xiàn)在更加始終如一，即使在低溫地區(qū)也一樣。 研究人員在多處地點(diǎn)考察了昆蟲(chóng)多樣性的現(xiàn)狀，包括溫帶的馬薩諸塞州的哈佛森林、熱帶的哥斯達(dá)黎加、以及位于不列顛哥倫比亞?。幽么笪鞑渴∶┯兄?千3百萬(wàn)年歷史前的麥克比化石層等。麥克比化石層曾經(jīng)也是溫度恒定區(qū)域。相比較而言，同哈佛森林相比，古代加拿大的昆蟲(chóng)多樣性跟現(xiàn)代的哥斯達(dá)黎加更為相似。研究報(bào)告發(fā)表在《古生物學(xué)》雜志上。 因此，我們得回過(guò)頭來(lái)重新想想——并不是熱帶才有著更豐富的生物多樣性。或許是現(xiàn)今溫帶的四季使得生物多樣性減少，因此花兒一年只開(kāi)放一次，而動(dòng)物們的繁殖期也減少到一年一次。